kernel/linux.git/include/linux/types.h, branch v6.12.80

types: Complement the aligned types with signed 64-bit one

2025-05-18T06:24:56+00:00

[ Upstream commit e4ca0e59c39442546866f3dd514a3a5956577daf ] Some user may want to use aligned signed 64-bit type. Provide it for them. Signed-off-by: Andy Shevchenko Link: https://patch.msgid.link/20240903180218.3640501-2-andriy.shevchenko@linux.intel.com Signed-off-by: Jonathan Cameron Stable-dep-of: 1bb942287e05 ("iio: accel: adxl355: Make timestamp 64-bit aligned using aligned_s64") Signed-off-by: Sasha Levin

ktime.h: move ktime_t to types.h

2023-12-21T00:26:30+00:00

ktime.h pulls in quite a few headers recursively (including printk.h) - this is going to help with trimming sched.h dependencies. Signed-off-by: Kent Overstreet

Merge tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-06-28T17:59:38+00:00

Pull non-mm updates from Andrew Morton: - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in top-level directories - Douglas Anderson has added a new "buddy" mode to the hardlockup detector. It permits the detector to work on architectures which cannot provide the required interrupts, by having CPUs periodically perform checks on other CPUs - Zhen Lei has enhanced kexec's ability to support two crash regions - Petr Mladek has done a lot of cleanup on the hard lockup detector's Kconfig entries - And the usual bunch of singleton patches in various places * tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits) kernel/time/posix-stubs.c: remove duplicated include ocfs2: remove redundant assignment to variable bit_off watchdog/hardlockup: fix typo in config HARDLOCKUP_DETECTOR_PREFER_BUDDY powerpc: move arch_trigger_cpumask_backtrace from nmi.h to irq.h devres: show which resource was invalid in __devm_ioremap_resource() watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH watchdog/sparc64: define HARDLOCKUP_DETECTOR_SPARC64 watchdog/hardlockup: make HAVE_NMI_WATCHDOG sparc64-specific watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h watchdog/hardlockup: make the config checks more straightforward watchdog/hardlockup: sort hardlockup detector related config values a logical way watchdog/hardlockup: move SMP barriers from common code to buddy code watchdog/buddy: simplify the dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY watchdog/buddy: don't copy the cpumask in watchdog_next_cpu() watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called watchdog/hardlockup: remove softlockup comment in touch_nmi_watchdog() watchdog/hardlockup: in watchdog_hardlockup_check() use cpumask_copy() watchdog/hardlockup: don't use raw_cpu_ptr() in watchdog_hardlockup_kick() watchdog/hardlockup: HAVE_NMI_WATCHDOG must implement watchdog_hardlockup_probe() watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails ...

add intptr_t

2023-06-10T00:44:13+00:00

Add signed intptr_t given that a) it is standard type and b) uintptr_t is in tree. Link: https://lkml.kernel.org/r/ed66b9e4-1fb7-45be-9bb9-d4bc291c691f@p183 Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton

types: Introduce [us]128

2023-06-05T07:36:35+00:00

Introduce [us]128 (when available). Unlike [us]64, ensure they are always naturally aligned. This also enables 128bit wide atomics (which require natural alignment) such as cmpxchg128(). Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Arnd Bergmann Reviewed-by: Mark Rutland Acked-by: Herbert Xu Tested-by: Mark Rutland Link: https://lore.kernel.org/r/20230531132323.385005581@infradead.org

atomics: Provide rcuref - scalable reference counting

2023-03-28T08:39:29+00:00

atomic_t based reference counting, including refcount_t, uses atomic_inc_not_zero() for acquiring a reference. atomic_inc_not_zero() is implemented with a atomic_try_cmpxchg() loop. High contention of the reference count leads to retry loops and scales badly. There is nothing to improve on this implementation as the semantics have to be preserved. Provide rcuref as a scalable alternative solution which is suitable for RCU managed objects. Similar to refcount_t it comes with overflow and underflow detection and mitigation. rcuref treats the underlying atomic_t as an unsigned integer and partitions this space into zones: 0x00000000 - 0x7FFFFFFF valid zone (1 .. (INT_MAX + 1) references) 0x80000000 - 0xBFFFFFFF saturation zone 0xC0000000 - 0xFFFFFFFE dead zone 0xFFFFFFFF no reference rcuref_get() unconditionally increments the reference count with atomic_add_negative_relaxed(). rcuref_put() unconditionally decrements the reference count with atomic_add_negative_release(). This unconditional increment avoids the inc_not_zero() problem, but requires a more complex implementation on the put() side when the count drops from 0 to -1. When this transition is detected then it is attempted to mark the reference count dead, by setting it to the midpoint of the dead zone with a single atomic_cmpxchg_release() operation. This operation can fail due to a concurrent rcuref_get() elevating the reference count from -1 to 0 again. If the unconditional increment in rcuref_get() hits a reference count which is marked dead (or saturated) it will detect it after the fact and bring back the reference count to the midpoint of the respective zone. The zones provide enough tolerance which makes it practically impossible to escape from a zone. The racy implementation of rcuref_put() requires to protect rcuref_put() against a grace period ending in order to prevent a subtle use after free. As RCU is the only mechanism which allows to protect against that, it is not possible to fully replace the atomic_inc_not_zero() based implementation of refcount_t with this scheme. The final drop is slightly more expensive than the atomic_dec_return() counterpart, but that's not the case which this is optimized for. The optimization is on the high frequeunt get()/put() pairs and their scalability. The performance of an uncontended rcuref_get()/put() pair where the put() is not dropping the last reference is still on par with the plain atomic operations, while at the same time providing overflow and underflow detection and mitigation. The performance of rcuref compared to plain atomic_inc_not_zero() and atomic_dec_return() based reference counting under contention: - Micro benchmark: All CPUs running a increment/decrement loop on an elevated reference count, which means the 0 to -1 transition never happens. The performance gain depends on microarchitecture and the number of CPUs and has been observed in the range of 1.3X to 4.7X - Conversion of dst_entry::__refcnt to rcuref and testing with the localhost memtier/memcached benchmark. That benchmark shows the reference count contention prominently. The performance gain depends on microarchitecture and the number of CPUs and has been observed in the range of 1.1X to 2.6X over the previous fix for the false sharing issue vs. struct dst_entry::__refcnt. When memtier is run over a real 1Gb network connection, there is a small gain on top of the false sharing fix. The two changes combined result in a 2%-5% total gain for that networked test. Reported-by: Wangyang Guo Reported-by: Arjan Van De Ven Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20230323102800.158429195@linutronix.de

lib/sort: Add priv pointer to swap function

2022-03-18T03:17:18+00:00

Adding support to have priv pointer in swap callback function. Following the initial change on cmp callback functions [1] and adding SWAP_WRAPPER macro to identify sort call of sort_r. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Reviewed-by: Masami Hiramatsu Link: https://lore.kernel.org/bpf/20220316122419.933957-2-jolsa@kernel.org [1] 4333fb96ca10 ("media: lib/sort.c: implement sort() variant taking context argument")

s390,alpha: switch to 64-bit ino_t

2021-02-13T16:17:53+00:00

s390 and alpha are the only 64 bit architectures with a 32-bit ino_t. Since this is quite unusual this causes bugs from time to time. See e.g. commit ebce3eb2f7ef ("ceph: fix inode number handling on arches with 32-bit ino_t") for an example. This (obviously) also prevents s390 and alpha to use 64-bit ino_t for tmpfs. See commit b85a7a8bb573 ("tmpfs: disallow CONFIG_TMPFS_INODE64 on s390"). Therefore switch both s390 and alpha to 64-bit ino_t. This should only have an effect on the ustat system call. To prevent ABI breakage define struct ustat compatible to the old layout and change sys_ustat() accordingly. Acked-by: Linus Torvalds Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

locking/atomic: Move ATOMIC_INIT into linux/types.h

2020-07-29T14:14:18+00:00

This patch moves ATOMIC_INIT from asm/atomic.h into linux/types.h. This allows users of atomic_t to use ATOMIC_INIT without having to include atomic.h as that way may lead to header loops. Signed-off-by: Herbert Xu Signed-off-by: Peter Zijlstra (Intel) Acked-by: Waiman Long Link: https://lkml.kernel.org/r/20200729123105.GB7047@gondor.apana.org.au

y2038: remove unused time32 interfaces

2020-02-21T19:22:15+00:00

No users remain, so kill these off before we grow new ones. Link: http://lkml.kernel.org/r/20200110154232.4104492-3-arnd@arndb.de Signed-off-by: Arnd Bergmann Acked-by: Thomas Gleixner Cc: Deepa Dinamani Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds